The Dahlias bloomed so well this summer that I didn’t want to dig them up for winter storage. If I want them to survive for next year, it’s always best to dig them up. That way I can see how large the tubers are getting and if they have any pests or disease. It also lets me divide the tubers and plan where to place them next year. I may not want them in the same place as this year.
I use a pitchfork and carefully dig around the base of the pant. I find by using a pitchfork I don’t slice through the tubers like I could with a shovel. I just pry the soil a bit and gently lift the whole tuberous clump out of the ground. The first thing you have to do is shake off as much soil as you can. I cut the foliage off the plant and add it to my compost bin. Once you have just the clump of tubers in your hand, place them in a sunny spot to dry out for the day. This will dry up any remaining soil clinging to the tubers. Once they are dry, shake the soil off again. You want to remove as much as you can. Check carefully with your fingers between each tuber to dislodge those stubborn soil clumps.
Once your Dahlia tubers are ready for storage you may want to tag them so you know which ones you are saving. Above I used a plant tag cut from a yogurt container and wrote the name of the variety on it. I used a one-holed punch to make a hole and threaded a string through to hold the tag on. Just tie the tag to the end of the stems that are left.
Be sure to cut back the stems on your Dahlias. They are only going to die back and you don’t need any rotting greens in your storage box. If you look at the photo above, this is not how you want to store them. There is too much stem left on the tubers.
I like to cut the stems down to about an inch from the tuber. This is when you will add your tag. Now your dahlia tubers are ready for their winter home.
I use a cardboard box for storing my tubers. I place a few labelled Dahlia tubers on top of a couple of inches of vermiculite. Note that I leave them spread apart in the box. If one does rot by chance, I don’t want rot spreading to the rest. I will then add a second layer of Dahlias into the box and keep covering with vermiculite.
Before storing your dahlias be sure to check tubers for signs of rot. The mother tuber will most likely rot in storage so its best to remove it. What does the mother tuber look like? It’s often a darker brown than the rest of the clump.
This is what you don’t want to keep. You don’t want to store any diseased looking tubers. I removed this large tuber from a clump when I saw the rot and tiny hole towards the bottom. You never know what little critter may be lurking in there. You also don’t want a rotten tuber as the rot could spread to all of them and ruin your tubers for next season.
I also discard the single tubers that fall off. If they don’t have a piece of stem and an eye where the new growth will come out, they most likely will not grow again.
After the first layer of dahlia tubers is in the box, add more vermiculite to cover them. You may find that some tubers are larger than others so one side may need more vermiculite. Once these are covered add another layer of tubers and top off with more vermiculite.
Place the lid on your box and label it. You will have to store your Dahlias in a cool garage that is frost-free. Between 40-50F is ideal for storing dahlias. Check on them in about six weeks to be sure they are not drying out. In the spring I like to start my Dahlias in the greenhouse to get them off to an early start. If you want to plant them outside they can go in according to your climate. Here we can plant them in late April, early May.
Here is a teaser for next year. This is Dahlia ‘Ferncliff Duo’, a flower developed by Ferncliff Gardens.
This is Dahlia ‘Honka’ which performed so well this year. So I hope I have you thinking about Dahlias for next years garden. I know I will be ordering some more. They make such great cut flowers!